Help for removing password for CASwell COB-H500

[daniel_sa]

Hi, I'm pulling my hair out with this x86 network device.

bios info: AMI aptio V
Hardware: CASwell COB-H500
its OEM product, no support is available.
Device has no monitor output, Screen is redirected to serial port(VT100).

I have already tried the list below.

- cmospwd  -> no luck

- I read the BIOS using ch341, and checked with UEFITool, I thought I could find something useful. All I could find was the invalid part, which was "161406223039397D161A17781D6065657C19"
I used this https://www.dcode.fr/xor-cipher tool to decode it; it was "CASwell(COB-H500)L"
I tried different combinations to enter the password with this text. None of them were successful.

- AMITSESetup region check -> all values were zero.  so I couldn't retrieve any hash.

- There was another SPI EEPROM under the CPU (no, it wasn't I2C); I removed it; the computer boots but still requests a password. I checked the eeprom file, and it looks like some executable is lying there because I found FINI text inside. The chip is ST M95128.

- It is not giving any code after unsuccessful password attempts. So no luck with that.

- sure cmos reset not works since password is hard-coded.

Could you please give me some hints?
Thank you.